Gaya APA

LANGBEIN, L, I. (1980). Discovering Whether Programs Work : A Guide to Statistical Methodsfor Program Evaluation . : LIBRARY OFF CONGRESS CATALOGIING.

Gaya MLA

LANGBEIN, LAURA, IRWIN. "Discovering Whether Programs Work : A Guide to Statistical Methodsfor Program Evaluation". : LIBRARY OFF CONGRESS CATALOGIING, 1980. Text.